MEIOTIC CHROMOSOME DYNAMICS IN NEOTROPICAL DEER

• Grant number: 24/09290-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: December 29, 2024
• End date: December 08, 2025
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: José Maurício Barbanti Duarte
• Grantee: Agda Maria Bernegossi
• Supervisor: Aurora Ruiz-Herrera
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil
• Institution abroad: Universitat Autònoma de Barcelona (UAB), Spain
• Associated to the scholarship: 21/14536-6 - Evolution and speciation of Neotropical deer: a cytogenetic and molecular approach., BP.DR

Abstract

Throughout the evolutionary process, genomic rearrangements arise within germ cell lines, during meiosis. Both genetic and mechanistic factors influence mammalian meiotic recombination landscapes. The former is shaped by the evolutionary history of each taxon and the latter by chromosomal reorganizations, which can alter meiotic recombination by suppressing recombination within chromosomes involved in rearrangement. Therefore, Neotropical deer represent a non-model group with intriguing chromosomal features for studying the functional and mechanistic implications of chromosomal reorganization. Species within this group exhibit a wide range of diploid numbers (from 32 to 70), intraspecific chromosomal polymorphisms associated with tandem and centric fusions, B chromosomes, and a multiple-sex chromosome system (XY1Y2). However, the implications of these chromosomal characteristics in meiosis remain largely understudied. This research aims to analyze the potential impact of meiosis on the rapid rate of chromosomal evolution observed in Neotropical deer and to understand how different types of chromosomal reorganization affect meiotic dynamics and recombination rates. Testicular tissues with and without heterozygous translocations from three Neotropical deer species will undergo a detailed analysis of meiotic dynamics. Histological characterization of the spermatogenesis process will be performed, followed by an analysis of prophase I dynamics, including chromosomal pairing, synapsis, and the formation of meiotic double-strand breaks. We intend to contribute to a better understanding of the dynamics of chromosomal evolution in Neotropical deer, as well as to the broader discussion on recombination diversity in mammals.